1. Field of the Invention
This invention relates to a wood working machine such as a wood working router.
2. Description of the Prior Art
A numerically controlled wood working router is conventionally known wherein a plurality of rams are mounted for up and down movement on a carriage mounted for horizontal sliding movement and a working head is carried on each of the rams. Also an automatic tool exchanging apparatus for a numerically controlled wood working router of the type mentioned is conventionally known and disclosed, for example, in Japanese Patent Laid-Open Application No. 2-59244. However, only one such automatic tool exchanging apparatus is provided for a numerically controlled wood working router while the latter includes a plurality of rams. Besides, such automatic tool exchanging apparatus is installed fixedly at a particular location, and accordingly, when a tool is to be exchanged, a particular working head on which the tool is to be changed is moved together with all of the other working heads to the location of the automatic tool exchanging apparatus, and then only the tool of the particular working head is exchanged.
With the arrangement, however, even when a tool is to be exchanged for one working head, working operations of all of the working heads must be stopped, and consequently, the operability is very low.
On the other hand, a conventional wood working router normally includes a dust collecting equipment for collecting wood chips produced by working by a sucking action of air to remove them. An exemplary one of such conventional dust collecting equipments is disclosed, for example, in Japanese Utility Model Publication No. 1-33290 wherein a motor for a spindle is accommodated in a dust collecting hood and a dust collecting passageway is formed between the motor and the hood. Another exemplary conventional dust collecting equipment is disclosed in Japanese Utility Model Publication No. 60-13605 wherein a housing for a motor serves also as a dust collecting hood. Such conventional dust collecting equipments, however, cannot assure a sufficiently wide dust collecting range. Then if the size of such dust collecting hood or motor housing is increased in order to increase the dust collecting range, also the size of the equipment is increased as much.